Temperature control for cloth driers



Nov. 28, 1933.

I F. E. KLAGES TEMPERATURE CONTROL FOR CLOTH DRIERS 2 Sheets-Sheet 1 Filed Nov. 12 1932 ,Nov. 28; 1933. v F. E. P. KLAGES 1,937,155

TEMPERATURE-CONTROL FOR CLOTH DRIERS Filed Nov. 12, 1932 2 Sheets-Sheet 2 J] If f Y J 7 F 3 TEBIPERATURE CONTROL FOR CLOTH ,DRIERS Frank E. P. Klages,

Park Ridge, 111., assignor to The Powers Regulator Company, Chicago, Ill.

Application November 12,

Serial No. 642,387

. .7 Claims.

It is customary to provide thermostatic means for regulating the temperature or in other. words, the amount of steam supplied to the drums and under normal operation this is sufficient and the results are entirely satisfactory. However, when a stoppage occurs for any of a number of reasons, the emergency frequently results in burning'of the cloth. This is due to the fact that the steam pressure builds up immediately due to the fact that there is not the progressive withdrawal of heat by the travel of the wet cloth over the drums. The thermostat will ultimately shut off the steam supply but the action of the thermostats that are best suited for that purpose is comparatively slow and before the steam supply is interrupted, the cloth will be scorched. This has been a serious difliculty which was not overcome until the addition of the improvement herein described. This. improvement consists in providing a relay in the fluid supply line to the shut ofi valve and connecting the relay to the steam space in the drums, the parts being so arranged that as soon as there is an abnormal premure of steam in the drums, this pressure acting on the relay will admit air under pressure directly to the shut-ofl valve and close it much earlier than would occur by the thermostat.

In some instances objection is made that the shut-oil action even when the described attachment is made is too slow'; in other words, that there is a lag both in opening and closing that should be avoided. It will be understood that in normal operation when the cloth has been running with a fairly uniform moisture content, the thermostatic regulator will maintain the steam valve in a position three-fourths to four-fifths closed. The springs in the thermostatic valve are so designed that this is accomplished with the pressure of three and a half pounds assuming a supply pressure of fifteen pounds and will be fully closed at a pressure of six pounds or thereabouts. When using the type of regulator contemplated herein and which is found to be generally satisfactory there is a substantial time lag while the pressure is being built up from three and a half pounds to six pounds at which point the steam valve will be fully closed and during this lag some e may be done to the cloth. In the apparatus illustrated as collateral to the principal idea I have illustrated means whereby this lag in closing is eliminated.

The invention will be more readily understood so by reference to the accompanying drawings in which:

Fig. ,1 is a view, partly diagrammatic, showing the application of, my improvement to a conventional cloth drier, and

Fig. 2 is a similar view showing the use of the improvement in connection with mechanism by which a more positive action is secured.

In the drawings I have shown a plurality of rotatable drums 10 mounted in suitable bearings carried on fhollowcolumns 11 to which steam is supplied by means of the pipe 12 and the branches 13. A control valve 14 of well known form is mounted in the pipe 12; and if desired a reducing valve 15 is also furnished. Air under pressure is supplied by means of the pipe 16 and a leak type thermostat 17 is interposed in the air supply pipe, the outletfrom the thermostat being by the pipe 18 to the control valve 14. The operating bulb 17a for the thermostat 17 is located so adjacent to the surface of a drum, a flexible tube 19 providing connection to the thermostat. The apparatus heretofore described has commonly been installed and my improvement consists in providing a so-called relay valve 20 which may be of conventional formand providing a steam pipe connection 21 thereto from one of the columns 11. A pipe 16a is connected to the pipe 16 from a source of fluid under pressure and an outlet pipe 22 with a restriction valve 23 therein is connected to the pipe 18 that leads to the control valve. I a

The operation is such that as the steam pres-. sure rises due to any cause such as the stoppa e of the machine, the pressure acting through the relay valve will open the connection between the pipe 16a tothe pipe 22 and thence to the pipe 18 whereby fluid under pressure is admitted directly from its source to the control valve and immediately close it or positions it so that the steam pressure will not be excessive.

This is in anticipation of the closing action of the thermostat 1'? which would occur at a consid erably later period. Therestriction valve 23 is provided in order to properly correlate the action of the respective parts and is used when the apparatus is installed in order to secure the desired action.

The details of the thermostat and the relay valve are unimportant so far as the idea here sought to be covered is concerned.

In the apparatus shown in Fig. 2 the elements already described are present and operate as set forth. In addition I provide a positive relay valve 24 having a pipe connection 25 to the main air line, and a pipe connection26 to the outlet pipe 2'7 from the thermostatic regulator, this pipe leading through the connection 28 to the steam shut-off valve 14. The outlet connection from the relay valve 24 is a pipe 29 that also connects to the pipe 28 and by a branch 30 to a pilot valve 31 located in the pipe 27. The pipe 2'7 acts as a continuation of the pipe 32 that extends from the gradual relay valve 33 that is operated by steam pressure admitted through the pipe 34, air being supplied to the relay valve by the pipe 35 connected to the source of air under pressure.

The operation takes place as follows: Whenever pressure builds up in the line 27, 28 due to the closing of the bleeder valve in the thermostatic regulator to say five pounds, at which point the steam valve 14- is about four-fifths closed, this pressure will act on the relay valve 24 to open a direct connection through the pipe 25 with the full air pressure (fifteen pounds or more), and this will be delivered through the pipe 29 to the steam valve. This pressure acting through the pipe 30 on the pilot valve will close the normal outlet from the regulator 17 to the steam valve, so that the air under high pressure will not leak through the regulator and so that when normal conditions are restored, the regulator 17 will operate under its normal conditions and without an'excess pressure.

As soon. as the thermostat 17a responds to a lower heat condition in the drums, the air pressure controlled by the thermostat 1'7 will be lowered to a point below five pounds and immediately the relay 24 will close off the direct air pressure connection, the excess pressure in the line 28 being exhausted through the restriction valve 23 or gradual relay 33.- Thus the steam valve will be immediately opened to a degree corresponding to the pressure released by the thermostat 1'7.

In the case of the construction shown in Fig. 2, the relay 33 will act to immediately close the steam valve whenever the steam pressure exceeds a predetermined amount. This will act considerably in advance of the action that would follow the functioning of the thermostat 1'7 and the relay" 24. During normal operation of the apparatus shown in Fig. 2'the control of the steam admission to the drums will be effected by the thermostat 17 and the relay 24, the action of the valve being gradual up to a point at which the valve is approximately four-fifths closed. Any increase in temperature beyond that point will through the action of the relay 24 serve to immediately close the steam valve. A reversal of this action will take place upon a return of normal conditions reflected by the thermostatic element; that is the steam valve' will first be,

opened to a substantial extent and then graduallyopened further if the conditions warrant.

While the device has been described for use as a cloth drier it will be understood that the construction and arrangement of parts with slight modifications is adapted for many other uses.

Obviously the form of the drier, the location and arrangement of the thermostat and the location and arrangement of the control apparatus by which the steam pressure is utilized are unimportant, and modifications may be made therein without departure from the spirit of my invention.

I claim:

1. Heat control for driers, comprising the combination with a plurality of drier drums and valve means for controlling the feeding of steam thereto, of a thermostat in position to be affected by the temperature of said drums for regulating said valve, and means operated by an abnormal steam pressure for supplementing the action of said thermostat to eifect an earlier closing of said valve than would occur under the action of said thermostat.

2. Heat control for driers, comprising the combination with a plurality of drier drums and valve means for controlling the feeding of steam thereto, of a thermostat in position to be affected by the temperature of said drums for regulating said valve, a source of fluid under pressure and a fluid pressure connection between said thermostat and said valve, a relay valve in said connection, and means operated by an abnormal steam pressure in said drums for operating said relay valve to admit fluid under pressure directly from its sourceto said connection to immediately reposition said valve.

3. Heat control for driers, comprising the combination with a plurality of drier drums and valve means for controlling the feeding of steam thereto, of a'thermostat in position to be afiected by the temperature of said drums for regulating said valve, a source of fluid under pressure and a fluid pressure connection between said thermostat and said valve, and means operated by the pressure of steam in said drums for admitting fluid under pressure directly to said valve to efiect an earlier closing thereof 1 than would occur under the action of said thermostat.

4. In a cloth drier, the combination of a plurality of rotatable drums, means for supplying a heating medium thereto, a fluid-pressu're-operated valve, a thermostat for controlling the supply of fluid under pressure to said valve, and means operated by an excess heat condition in said drums for admitting fluid under pressure to said valve independently of said thermostat.

5. Heat control for driers, comprising the com bination with a plurality of drier drums and valve means for controlling the feeding of steam thereto, of a thermostat in position to be affected by the temperature of said drums for regulating said valve, means operated by an abnormal steam pressure for supplementing the action of said thermostat to effect an earlier closing. of said valve than would occur under the action of said thermostat, and means operating under a pressure built up by said thermostat less than the pressure necessary to close said valve for immediately applying a higher pressure to said valve for positioning the same.

6. In combination, drying means, means for supplying a heating medium thereto, a fluid-pressure-operated valve, a thermostat for controlling the operation of said valve by controlling the supply of fluid under pressure to said valve, and means operating under a pressure in the fluid supply line to said valveless than the pressure.

necessary to close said valve for opening a connection to a source of fluid under sufliciently high pressure to immediately reposition said valve.

7. In combination, drying means, means for supplying a heating medium thereto, a fluid-pressure-operated valve, a thermostat for controlling the operation of said valve by controlling the supply of fluid under pressure to said valve. means operating under a pressure in the fluid supply line to said valve for opening a comma:-

tion to a source of fluid under sumcientlv high pressure to immediateLv reposition said valve, and 

